If you are using a cPanel based hosting account and suddenly your website stopped delivering emails from form submissions or the PHP “mail” function, open your cPanel and head over to “Email Deliverability”.
Cpanel will list your domains and email deliverability status.
In my case (and I believe in most cases) you will have a notification about missing DKIM setup.
Fortunately, cPanel offer to repair the issue automatically. Let it do the repair with the suggested setup.
Hopefully now your emails will start arriving correctly.
The above also applies to WordPress forms generated by plugins such as Contact Form 7, WPForms and others.
Still not working? You can setup SMTP via Gmail or other services. Need help? Contact me for help – form on the right ->